Oliver, GD, Washington, JK, Barfield, JW, Gascon, SS, and Gilmer, G. Quantitative analysis of proximal and distal kinetic chain musculature during dynamic exercises. J Strength Cond Res 32(6): 1545-1553, 2018-Proximal to distal sequencing for the dynamic movement of throwing is dependent on the movement and stability of the lumbopelvic-hip complex (LPHC) and scapula. Although the need for proximal stability for distal mobility has been vastly documented, pre-throwing programs tend to focus on the traditional rotator cuff activation exercises before long toss. Thus, it was the purpose of this study to describe muscle activations of LPHC stabilizing musculature (bilateral gluteus medius and maximus) and scapular stabilizing musculature (dominant side latissimus dorsi, lower trapezius, upper trapezius, and serratus anterior) during 5 kinetic chain exercises that could be implemented in a throwing program. It was hypothesized that both the LPHC and the scapular stabilizing musculature would exhibit moderate to high activation during all the selected kinetic chain exercises. Nineteen healthy college students (23.2 ± 7.2 years; 176.7 ± 17.9 cm; 78.0 ± 28.6 kg) participated. Surface electromyography was used to measure muscle activity in the LPHC and scapular stabilizing musculature during 5 kinetic chain exercises. A nonparametric Friedman test revealed significantly different muscle activations as a factor of exercise for each muscle, χ(18) = 417.220, p < 0.001. The 5 kinetic chain exercises successfully elicited moderate to high muscle activation in all musculature, except the upper trapezius. Because greater muscle activation of the LPHC and scapular stabilizers are crucial during a throwing task, these exercises are recommended for pre-throwing program implementation because they efficiently prepare the stabilizing musculature for lengthy or strenuous throwing tasks, resulting in a potential decrease in injury susceptibility.

Oliver, GD, Plummer, HA, and Gascon, SS. Electromyographic analysis of traditional and kinetic chain exercises for dynamic shoulder movements. J Strength Cond Res 30(11): 3146-3154, 2016-Proper utilization of the kinetic chain allows for efficient kinetic energy transfer from the proximal segments to the distal segments. The aims of this study were to describe muscle activations in 4 kinetic chain prethrowing exercises and compare these muscle activations with 3 traditional resistance-band exercises. Twenty-six healthy college students (22.9 ± 3.4 years; 172.2 ± 8.6 cm; 74.2 ± 16.3 kg), regardless of gender, participated. Surface electromyographic data were recorded for selected pelvic and scapular musculature while subjects performed the exercises. The exercises included airplane (single-leg balance with weight-bearing hip flexed to 90° and non-weight-bearing hip extended) while performing alternating repetitions of external and internal shoulder rotation, lunge, Get Up, single-leg balance, and resistance band I, T, and Y. A repeated-measures analysis of variance, with a factor of exercise (8 different levels), was used. Post hoc analyses were used for each muscle to determine the statistically significant differences between exercises. The results reveal the greatest activation occurred during the 2 airplane exercises than all the other exercises. The results of this study help to establish surface electromyographic data for selected pelvis and scapula musculature during a series of kinetic chain and resistance-band exercises. Understanding the muscle activations during these exercises can assist clinicians and coaches in choosing the appropriate exercises to implement for individuals involved in dynamic shoulder movement.

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Background:The scapula is a critical link utilized in the kinetic chain to achieve efficient overhead movement and transfer energy from the lower extremity to the upper extremity. Additionally, daily activities such as sitting at a computer or driving in a car may negatively influence an individual's ability to maintain proper body posture and therefore compromise those movements. To reduce these negative influences, posture garments have been designed to cue the individual in maintaining and improving posture and alignment, specifically targeting scapular positioning.Purpose: The purpose of this study was to compare scapular positioning between an IntelliSkin™ posture-cueing compression garment and a generic performance garment on scapular kinematics during static standing. Study Design: Case control.Methods: Forty active females (1.68 ± 0.07 m; 67.29 ± 11.25 kg) stood in a natural standing position while wearing two different garments: IntelliSkin™ posture-cueing compression garment and a generic performance garment. Kinematic data were collected at 100 Hz using an electromagnetic tracking system (trakSTAR™, Ascension Technologies, Inc., Burlington, VT, USA) synced with The MotionMonitor ® (Innovative Sports Training, Chicago, IL., USA). Results:Repeated measures ANOVAs revealed a statistically significant Shirt by Side interaction for scapular protraction/retraction (F(1,39) = 52.91, p ≤ 0.05) and main-effect of Shirt for scapula anterior/posterior tilt (F(1,39) = 96.45, p ≤ 0.05). Individuals showed increased retraction and posterior tilt while wearing the IntelliSkin™ posture-cueing compression garment. Conclusion:The results of the current study indicate that the IntelliSkin™ posture-cueing compression garment improved scapular positioning during static standing posture. The IntelliSkin™ posture-cueing compression garment may provide clinicians an adjunct strategy to include with rehabilitative protocols. Level of Evidence: Diagnosis, Level 3

The hip abductor fatigue protocol utilized in this study did not significantly alter trunk and upper extremity throwing kinematics. The lack of changes may indicate that fatigue of the hip abductors does not contribute to trunk and shoulder kinematics during throwing or the protocol may not have been sport-specific enough to alter kinematics.